Meningitis is one of the most dreaded acute medical emergencies presenting to the emergency department (ED). It has a high fatality rate if early diagnosis is not made and treatment initiated. In this report we present a rare case of meningitis. We report this case to make readers aware of an infection that can potentially cause an epidemic, similar to a recent occurrence in China in June 2005.

CASE REPORT

A 35-year-old male butcher presented to our ED with a 6-h history of confusion, ataxia and headache. He had two episodes of vomiting and had become increasingly drowsy and restless over the past 4 h. The ambulance crew reported that they needed to use force to restrain him and had administered rectal diazepam. Interestingly, he had presented to the ED earlier that day with backache and had been discharged with a prescription of tramadol; he had taken a total of 200 mg of tramadol in the past 12 h. On arrival, he had a Glasgow coma score of 7/15 (E 1, V 1, M 5) but was maintaining a good airway, temperature 39.8°C, pulse rate 110, blood pressure 130/76 mm Hg with oxygen saturations of 99%. General physical examination revealed numerous ecchymotic and purpuric rashes on the trunk and limbs. Cardiovascular, abdominal and respiratory examinations were unremarkable and neurological examination revealed bilateral reactive pupils, mild neck stiffness and bilateral withdrawal plantar reflexes. He was immediately started on oxygen, intravenous fluids, rectal paracetamol was prescribed and routine investigations including blood cultures were requested.

Progressive headache associated with confusion raised a high suspicion of meningitis or possible encephalitis in this young man. Blood investigations showed a raised white cell count of 23.4 × 10³/mm³ with a neutrophilia of 21.0 × 10³/mm³ and a C-reactive protein level of 249 mg/dl. A diagnosis of meningitis was made and intravenous ceftriaxone was started in the ED and the patient was referred to the physicians. A computed tomographic imaging of the brain performed later was normal and subsequently he had a lumbar puncture that showed turbid cloudy fluid with a white cell count of 3630/mm³, a red cell count of 474/mm³, protein of 149 g/l and Streptococcus suis sensitive to cephalosporins was cultured. Due to a falling Glasgow coma score, the patient was transferred to the intensive therapy unit for assisted ventilation, where he improved with antibiotics—ceftriaxone, gentamicin and supportive care. He was weaned off the ventilator in next 2 days and made rapid progress with rehabilitation, having no neurological sequelae. It was subsequently discovered that the patient had sustained a cut to his hand while handling uncooked pork meat at work, 2 days before presentation. This injury went unnoticed in the ED and was the likely site of entry of the infection.

DISCUSSION

S suis is a Gram-positive, facultatively anaerobic coccus that has been implicated as the cause of a wide range of clinical disease syndromes in swine and other domestic animals. S suis has also been implicated in human disease, especially among abattoir workers and swine and pork handlers. S suis infection is found in all pig-raising countries. Worldwide, hospitals in Hong Kong, The Netherlands, Greece, Spain, Japan (S suis type 2), Croatia (S suis type 1), Taiwan, Singapore, United Kingdom, Austria, Belgium, Canada, Italy, New Zealand, Sweden and Latin America have reported cases. Cases in Germany, The Netherlands and France have been acquired from wild boar. Occupational seropositivity has been documented in New Zealand and The Netherlands. Virtually all patients have been farmers and butchers, of whom 80% were men. Most had been involved in butchering sick pigs or selling the pork.1 There has been no evidence of human-to-human transmission.2

Reported symptoms include high fever, malaise, nausea and vomiting, followed by meningitis, pneumonia, subcutaneous haemorrhage, polyarthritis, toxic shock and coma in severe cases. The time from pig exposure to the onset of symptoms is short and the disease progresses rapidly. In humans, 80% of all cases are due to meningitis, and it is found to be one of the third commonest causes of meningitis in Hong Kong.3 Toxic shock syndrome with haemorrhagic manifestations rarely develops.

The organism is found to be sensitive to penicillin and cephalosporin. Complications resulting from S suis meningitis include neurological sequelae such as ataxia, disturbance of gait and bilateral hearing impairment.2

The WHO released an epidemic and pandemic alert, after an outbreak of S suis infection in China during the summer of 2005, with 206 cases reported and a case fatality rate of 18%. There was a suggestion that the outbreak was associated with a new strain of the bacterium4 more able to adapt to humans.

Further occurrences of S suis illness can be prevented by increasing awareness of the disease with the education of farmers, pig and pork handlers. The Health Protection Agency recognises this infection as an occupational hazard, but not as a notifiable disease. Due to the virulent nature of the infection, people at risk should be educated about the warning symptoms, signs and advised to seek medical help early. Vaccines with uncertain efficacy have been used in swine to prevent virulent infection; however, vaccines for humans at risk are yet to be developed.